Selective retransmission method for uplink overhead reduction

ABSTRACT

Systems and methods are provided for an improved link budged resulting from reduced overhead. The method includes determining a signal to noise and interference ratio (SINR) at a wireless device, comparing the SINR to a predetermined threshold and determining the SINR at the wireless device meets the predetermined threshold. The method additionally includes disabling a hybrid automatic repeat request (HARD) retransmission mechanism for the wireless device based on the determination that the SINR at the wireless devices meets the predetermined threshold.

TECHNICAL BACKGROUND

A wireless network, such as a cellular network, can include an accessnode (e.g., base station) serving multiple wireless devices or userequipment (UE) in a geographical area covered by a radio frequency (RF)transmission provided by the access node. As technology has evolved,different carriers within the cellular network may utilize differenttypes of radio access technologies (RATs). RATs can include, forexample, 3G RATs (e.g., GSM, CDMA etc.), 4G RATs (e.g., WiMax, LTE,etc.), and 5G RATs (new radio (NR)).

As access nodes have evolved, networks may include a combination ofmultiple access node such as 4G LTE evolved NodeBs (eNodeBs) and 5G NRnext generation NodeBs (gNodeBs) or alternatively may be exclusively 4Gor 5G cellular systems. Wireless devices closer to a 5G antenna are morelikely to receive the benefits of the 5G technology. Access to high dataspeeds is improved if a high signal to interference and noise ratio(SINR) is present. Accordingly, when a wireless device moves furtherfrom an antenna, the wireless device is likely to experience a decreasein quality of service (QoS).

In order to avoid prolonged decreases in QoS or other performanceparameters, wireless devices periodically send channel statusinformation (CSI) reports to an access node in the network. The CSIreport tells the access node how good or bad a channel is at a specifictime. The CSI report may contain for example, a channel qualityindicator (CQI), a precoding matrix index (PMI), and a rank indicator(RI), CSI-RS Resource Indicator (CRI), SS/PBCH Resource Block Indicator(SSBRI), and layer indicator (LI) as well as other measurements. Often,the wireless devices report in a periodic time interval configured by ahigher layer. While more frequent CSI reporting can improve QoS for awireless device, it also increases overhead on wireless communicationslinks.

Furthermore, in order to increase transmission reliability in wirelesscommunications, systems employ retransmission mechanisms such thatwireless devices can request retransmission of information which iseither not received or cannot be properly decoded. For example, UEs andaccess nodes such as gNodeBs may employ a hybrid automatic repeatrequest (HARQ) mechanism. In HARQ, a sender, such as a gNodeB, can berequested by a receiver, such as a UE or wireless device, to retransmita package when a previous transmission attempt was unsuccessful. HARQsystems utilize forward error correction (FEC) information, whichincreases transmission accuracy at the cost of transmission efficiencydue to the increased overhead on the wireless communication link.

Thus, existing systems for improving reliability and QoS for wirelessdevices often result in excessive overhead on wireless communicationlinks. Accordingly, a solution is needed that maintains QoS andreliability for wireless devices while reducing the excessive overheadcreated by existing processes for improving reliability and maintainingQoS.

Overview

Exemplary embodiments described herein include systems, methods, andnon-transitory computer readable mediums for reducing uplink overhead byselecting a retransmission mechanism. An exemplary method includesdetermining a signal to noise and interference ratio (SINR) at awireless device, comparing the SINR to a predetermined threshold, andetermining the SINR at the wireless device meets the predeterminedthreshold. The method additionally includes disabling a hybrid automaticrepeat request (HARQ) retransmission mechanism for the wireless device.

An additional exemplary embodiment includes an access node having atleast one processor for performing multiple operations. The operationsinclude determining a signal to noise and interference ratio (SINR) at awireless device, comparing the SINR to a predetermined threshold, anddetermining the SINR at the wireless device meets the predeterminedthreshold. The operations additionally include disabling a hybridautomatic repeat request (HARQ) retransmission mechanism for thewireless device in response to the determination that the SINR meets thepredetermined threshold.

Yet an additional exemplary embodiment includes a non-transitorycomputer readable medium, programmed to perform multiple operations. Theoperations include comparing a SINR at a wireless device to apredetermined SINR threshold and utilizing a HARQ retransmissionmechanism for the wireless device when the SINR does not meet thepredetermined SINR threshold. The operations additionally includedisabling the HARQ retransmission mechanism for the wireless device whenthe SINR meets the predetermined SINR threshold.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an exemplary system for wireless communication, inaccordance with the disclosed embodiments.

FIG. 2 illustrates an exemplary configuration of retransmissionmechanisms available for a wireless device in accordance with disclosedembodiments.

FIG. 3 depicts an access node in accordance with disclosed embodiments.

FIG. 4 is a flow diagram depicting an access node and wireless deviceselecting a retransmission mode in accordance with disclosedembodiments.

FIG. 5 is a flow chart depicting a method for selecting a retransmissionmode in accordance with disclosed embodiments.

FIG. 6 is a flow chart depicting an additional method for selecting aretransmission mode in accordance with disclosed embodiments.

DETAILED DESCRIPTION

Exemplary embodiments described herein include systems, methods, andcomputer readable mediums for reducing uplink overhead by dynamicallyselecting a retransmission method. In particular, embodiments set forthherein include enhanced logic for evaluating a performance parameter fora wireless device in comparison to a threshold and dynamically selectinga retransmission mode for the wireless device based on whether theperformance parameter meets a particular threshold.

In embodiments provided herein, enhanced logic dynamically disables aHARQ retransmission mechanism for a wireless device, when theperformance parameter meets a predetermined threshold. When the HARQretransmission mechanism is disabled, the wireless device may utilizeretransmission mechanism from a higher layer, such as a radio linkcontrol (RLC) retransmission mechanism. While the RLC retransmissionmechanism is slower than the HARQ retransmission mechanism, it does notcreate as much uplink overload as the HARQ retransmission mechanism.Additionally, wireless devices may utilize a PDCP retransmission mode asan alternative in some circumstances, particularly when a handoverthreshold has been met.

Thus, in embodiments set forth herein, a dynamic media access control(MAC) HARQ based mechanism is provided so that if the performance of aUE meets a predetermined threshold, HARQ is paused and the wirelessdevice relies on RLC and/or other upper protocol level retransmissions.Accordingly, wireless devices within a certain proximity to an accessnode will typically have the HARQ mechanism disabled. Wireless devicesfurther from the access node that do not meet the performance thresholdwill continue to utilize MAC HARQ retransmissions. Thus, for example,wireless devices with lower downlink SINR will carry on with standardMAC level HARQ retransmission mechanism. Methods and systems describedherein thereby reduce uplink overload on the physical shared uplinkchannel (PUSCH) for high downlink rates, such as for example, 50 Mbps or100 Mbps or 1000 Mbps streams. Further, the process described hereinserves to conserve battery and processing power for wireless devices andimprove latency.

In embodiments disclosed herein, a cell or wireless network may beprovided by an access node. The access node may utilize one or moreantennas to communicate with wireless devices or UEs. Performance at aparticular wireless device may be dependent on a number of factorsincluding, for example, signal strength parameters and interferenceindicators. Values such as signal to interference and noise ratio(SINR), reference signal received power (RSRP), reference signalreceived quality (RSRQ) or other measurements may be periodicallymeasured and reported by the wireless devices over a communicationnetwork to an access node. Additional signal performance parameters maybe reported, including, for example, channel quality indicator (CQI),and rank index (RI).

In particular, embodiments disclosed herein include an improved methodfor minimizing uplink overhead that results in conservation of batteryand processing power and improved overall performance for networkdevices. By selecting a particular retransmission method based onperformance parameters of the wireless device, performance is maintainedfor wireless devices in the network and uplink overhead and latency arereduced. Other triggers may alternatively be utilized as the performanceof a wireless device may be dependent on a number of factors including,for example, antenna performance parameters, network loading conditions,and wireless device location within a cell or a sector.

Thus, as described herein, detecting the triggering event may includedetecting a signal strength meeting a predetermined threshold. Forexample, received signal received power (RSRP) or SINR at the wirelessdevice may diminish to a level such that the connection is interrupted.However, when wireless devices move closer to an access node and nointerference is present, the signal strength increases. When signalstrength for a wireless device meets a predetermined network definedthreshold, HARQ may be disabled. Further, the signal strength may bemonitored on a continual basis, such that when the signal strength forthe wireless device deteriorates, HARQ may again be enabled.

In embodiments set forth herein, the network may be a 4G LTE network 5GNR network or a combined 4G/5G network. Other networks are within scopeof the disclosure. Wireless devices may travel throughout the networkmeasuring and reporting performance parameters. Methods performed hereinmay be performed in response to the receipt and processing of measuredperformance parameters from the wireless devices. The access node, forexample a gNodeB, may signal the wireless device and instruct it tocompletely eliminate mac HARQ and run on RLC and upper levelretransmission mechanisms only.

The term “wireless device” refers to any wireless device included in awireless network. For example, the term “wireless device” may include arelay node, which may communicate with an access node. The term“wireless device” may also include an end-user wireless device, whichmay communicate with the access node through the relay node. The term“wireless device” may further include an end-user wireless device thatcommunicates with the access node directly without being relayed by arelay node.

The terms “transmit” and “transmission” in data communication may alsoencompass receive and receiving data. For example, “data transmissionrate” may refer to a rate at which the data is transmitted by a wirelessdevice and/or a rate at which the data is received by the wirelessdevice.

An exemplary system described herein includes at least an access node(or base station), such as an eNodeB, or gNodeB, and a plurality ofend-user wireless devices. For illustrative purposes and simplicity, thedisclosed technology will be illustrated and discussed as beingimplemented in the communications between an access node (e.g., a basestation) and a wireless device (e.g., an end-user wireless device). Itis understood that the disclosed technology may also be applied tocommunication between an end-user wireless device and other networkresources, such as relay nodes, controller nodes, antennas, etc.Further, multiple access nodes may be utilized. For example, somewireless devices may communicate with an LTE eNodeB and others maycommunicate with an NR gNodeB.

In addition to the systems and methods described herein, the operationsof for selecting retransmission methods may be implemented ascomputer-readable instructions or methods and processing nodes on thenetwork for executing the instructions or methods. The processing nodemay include a processor included in the access node or a processorincluded in any controller node in the wireless network that is coupledto the access node.

FIG. 1 depicts an exemplary system 100 for use in conjunction withembodiments disclosed herein. System 100 comprises a communicationnetwork 101, gateway 102, controller node 104, 5G core 108, access nodes110 and 120, and wireless devices 131, 132, and 133. Access node 110 isillustrated as having a coverage area 115, and access node 120 isillustrated as having a coverage area 125. As illustrated, the coveragearea 115 may be larger than the coverage area 125. This may result fromthe access node 110 having higher power transmission capabilities thanthe access node 120. For example, the access node 120 may be capable ofa 320 W downlink transmission power and the access node 120 may becapable of a 120 W downlink transmission power.

Wireless device 131 is located within coverage area 115 and accessesnetwork services using a wireless communication link 112 from accessnode 110. Wireless device 132 is located within coverage area 125 andaccesses network services from access node 120 via another wirelesscommunication link 114. Further, wireless device 133 is located withinoverlapping coverage area formed by an overlap of coverage areas 115,125. For example, access nodes 110, 120 may be configured to deployindividual sectors and the overlapping coverage area may comprise anyoverlapping coverage area of the sectors. The wireless devices 131, 132,and 133 may travel between the coverage areas 115 and 125, thus beingvariously connected to access nodes 110 and 120.

In the illustration of FIG. 1 , both the first access node 110 and thesecond access node may be connected to the communication network 101 viaboth an LTE path (including the gateway node 102) and an NR path(including the 5G core 108). However, in practical implementations oneor both of the first access node 110 and the second access node 120 maybe connected to the communication network 101 via only a single RATpath. In any event, the first access node and the second access node110, 120 communicate with the gateway node 102, the controller node 104,and/or the 5G core 108 via respective communication links, each of whichmay be a direct link (e.g., an X2 link or the like).

Access nodes 110, 120 can be any network node configured to providecommunication between wireless devices 131, 132, 133 and communicationnetwork 101, including standard access nodes and/or short range, lowpower, small access nodes. For instance, access nodes 110, 120 mayinclude any standard access node, such as a macrocell access node, basetransceiver station, a radio base station, gNodeBs, eNodeBs, or thelike. In an exemplary embodiment, a macrocell access node can have acoverage area 115, 125 in the range of approximately five kilometers tothirty five kilometers and an output power in the tens of watts. Inother embodiments, access nodes 110, 120 can be a small access nodeincluding a microcell access node, a picocell access node, a femtocellaccess node, or the like such as a home NodeB or a home eNodeB device.Moreover, it is noted that while access nodes 110, 120 are illustratedin FIG. 1 , any number of access nodes can be implemented within system100.

Access nodes 110, 120 can comprise processors and associated circuitryto execute or direct the execution of computer-readable instructions toperform operations such as those further described herein. Briefly,access nodes 110, 120 can retrieve and execute software from storage,which can include a disk drive, a flash drive, memory circuitry, or someother memory device, and which can be local or remotely accessible. Thesoftware comprises computer programs, firmware, or some other form ofmachine-readable instructions, and may include an operating system,utilities, drivers, network interfaces, applications, or some other typeof software, including combinations thereof. Further, access nodes 110,120 can receive instructions and other input at a user interface. Accessnodes 110, 120 communicate with gateway node 102 and controller node 104via communication links 106, 107. Access nodes 110, 120 may communicatewith each other and with other access nodes (not shown) using a directlink such as an X2 link or similar.

Wireless devices 131, 132, 133 may be any device, system, combination ofdevices, or other such communication platform capable of communicatingwirelessly with access nodes 110, 120 using one or more frequency bandsdeployed therefrom. Wireless devices 131, 132, 133 may be, for example,a mobile phone, a wireless phone, a wireless modem, a personal digitalassistant (PDA), a voice over internet protocol (VoIP) phone, a voiceover packet (VOP) phone, or a soft phone, as well as other types ofdevices or systems that can exchange audio or data via access nodes 110,120. Other types of communication platforms are possible.

Communication network 101 can be a wired and/or wireless communicationnetwork, and can comprise processing nodes, routers, gateways, andphysical and/or wireless data links for carrying data among variousnetwork elements, including combinations thereof, and can include alocal area network a wide area network, and an internetwork (includingthe Internet). Communication network 101 can be capable of carryingdata, for example, to support voice, push-to-talk, broadcast video, anddata communications by wireless devices 131-133. Wireless networkprotocols can comprise MBMS, code division multiple access (CDMA) 1×RTT,Global System for Mobile communications (GSM), Universal MobileTelecommunications System (UMTS), High-Speed Packet Access (HSPA),Evolution Data Optimized (EV-DO), EV-DO rev. A, Third GenerationPartnership Project Long Term Evolution (3GPP LTE), WorldwideInteroperability for Microwave Access (WiMAX), Fourth Generationbroadband cellular (4G, LTE Advanced, etc.), and Fifth Generation mobilenetworks or wireless systems (5G, 5G New Radio (“5G NR”), or 5G LTE).Wired network protocols that may be utilized by communication network101 comprise Ethernet, Fast Ethernet, Gigabit Ethernet, Local Talk (suchas Carrier Sense Multiple Access with Collision Avoidance), Token Ring,Fiber Distributed Data Interface (FDDI), and Asynchronous Transfer Mode(ATM). Communication network 101 can also comprise additional basestations, controller nodes, telephony switches, internet routers,network gateways, computer systems, communication links, or some othertype of communication equipment, and combinations thereof.

Communication links 106, 107 can use various communication media, suchas air, space, metal, optical fiber, or some other signal propagationpath—including combinations thereof. Communication links 106, 107 can bewired or wireless and use various communication protocols such asInternet, Internet protocol (IP), local-area network (LAN), opticalnetworking, hybrid fiber coax (HFC), telephony, T1, or some othercommunication format—including combinations, improvements, or variationsthereof. Wireless communication links can be a radio frequency,microwave, infrared, or other similar signal, and can use a suitablecommunication protocol, for example, Global System for Mobiletelecommunications (GSM), Code Division Multiple Access (CDMA),Worldwide Interoperability for Microwave Access (WiMAX), Long TermEvolution (LTE), 5G NR, or combinations thereof. Communication links106, 107 may include S1 communication links. Other wireless protocolscan also be used. Communication links 106, 107 can be a direct link ormight include various equipment, intermediate components, systems, andnetworks. Communication links 106, 107 may comprise many differentsignals sharing the same link.

Gateway node 102 can be any network node configured to interface withother network nodes using various protocols. Gateway node 102 cancommunicate user data over system 100. Gateway node 102 can be astandalone computing device, computing system, or network component, andcan be accessible, for example, by a wired or wireless connection, orthrough an indirect connection such as through a computer network orcommunication network. For example, gateway node 102 can include aserving gateway (SGW) and/or a public data network gateway (PGW), etc.One of ordinary skill in the art would recognize that gateway node 102is not limited to any specific technology architecture, such as LongTerm Evolution (LTE) or 5G NR can be used with any network architectureand/or protocol.

Gateway node 102 can comprise a processor and associated circuitry toexecute or direct the execution of computer-readable instructions toobtain information. Gateway node 102 can retrieve and execute softwarefrom storage, which can include a disk drive, a flash drive, memorycircuitry, or some other memory device, and which can be local orremotely accessible. The software comprises computer programs, firmware,or some other form of machine-readable instructions, and may include anoperating system, utilities, drivers, network interfaces, applications,or some other type of software, including combinations thereof. Gatewaynode 102 can receive instructions and other input at a user interface.

Controller node 104 can be any network node configured to communicateinformation and/or control information over system 100. Controller node104 can be configured to transmit control information associated with ahandover procedure. Controller node 104 can be a standalone computingdevice, computing system, or network component, and can be accessible,for example, by a wired or wireless connection, or through an indirectconnection such as through a computer network or communication network.For example, controller node 104 can include a mobility managemententity (MME), a Home Subscriber Server (HSS), a Policy Control andCharging Rules Function (PCRF), an authentication, authorization, andaccounting (AAA) node, a rights management server (RMS), a subscriberprovisioning server (SPS), a policy server, etc. One of ordinary skillin the art would recognize that controller node 104 is not limited toany specific technology architecture, such as Long Term Evolution (LTE)or 5G NR can be used with any network architecture and/or protocol.

Controller node 104 can comprise a processor and associated circuitry toexecute or direct the execution of computer-readable instructions toobtain information. Controller node 104 can retrieve and executesoftware from storage, which can include a disk drive, a flash drive,memory circuitry, or some other memory device, and which can be local orremotely accessible. In an exemplary embodiment, controller node 104includes a database 105 for storing information, such as locationinformation for overlapping coverage area 135, positions of wirelessdevices 131, 132, 133, transmission power capabilities, schedulingschemes and resource allocations for each of access nodes 110, 120 andwireless devices connected thereto, and so on. This information may berequested by or shared with access nodes 110, 120 via communicationlinks 106, 107, X2 connections, and so on. The software comprisescomputer programs, firmware, or some other form of machine-readableinstructions, and may include an operating system, utilities, drivers,network interfaces, applications, or some other type of software, andcombinations thereof. Controller node 104 can receive instructions andother input at a user interface.

Further, a scheduling entity (within, for example, one or both of accessnodes 110, 120, or controller node 104) may be configured to allocateresources and select a retransmission method in accordance withembodiments set forth herein, thereby improving wireless deviceperformance throughout the coverage area.

The core 108 may be a 5G core collectively implementing several controlplane network functions (NFs) and user plane NFs. The control plane NFsinclude but are not limited to a Network Slice Selection Function(NSSF), a Network Exposure Function (NEF), a NF Repository Function(NRF), a Policy Control Function (PCF), a Unified Data Management (UDM),an Application Function (AF), a Short Message Service Function (SMSF), aCore Access and Mobility management Function (AMF), a Session ManagementFunction (SMF), and an Authentication Server Function (AUSF). The userplane NFs include but are not limited to a Unified Data Repository (UDR)and a UPF. Control plane NFs can provide one or more NFs based on arequest-response or subscribe-notify model. The NFs may form a microservices-based architecture, which may include network functionsdistributed over different cloud infrastructures. Additionally, manyservices may span different network functions and domains that work inunison.

The NRF maintains the list of available network functions and theirprofiles. The NRF maintains an updated repository of the networkcomponents along with services provided by each of the elements in thecore network. The NRF additionally provides a discovery mechanism thatallows the elements to discover each other. The NRF provides aregistration function that allows each network function to register aprofile and a list of services with the NRF. It also performs servicesregistration and discovery so that different network functions can findeach other. As one example, the SMF, which is registered to NRF, becomesdiscoverable by the AMF when a UE or other device tries to access aservice type served by the SMF. The NRF broadcasts available servicesonce they are registered in the 5G core 108. To use other networkfunctions, registered functions can send service requests to the NRF.

The UDM interfaces with NFs such as AMF and SMF so that relevant databecomes available to AMF and SMF. The UDM generates authenticationvectors when requested by the AUSF, which acts as an authenticationserver. The AMF performs the role of access point to the 5G core 108,thereby terminating RAN control plane and UE traffic originating oneither the N1 or N2 reference interface. In the 5G core 108, thefunctionality of the 4G Mobility Management Entity (MME) is decomposedinto the AMF and the SMF. The AMF receives all connection and sessionrelated information from the UE using N1 and N2 interfaces, and isresponsible for handling connection and mobility management tasks.

The UDR may provide unified data storage accessible to both controlplane NFs and user plane NFs. Thus, the UDR may be a repository sharedbetween control plane NFs and the UPF. The UDR may include informationabout subscribers, application-specific data, and policy data. The UDRcan store structured data that can be exposed to an NF. The UPF mayperform operations including, but not limited to, packet routing andforwarding, packet inspection, policy enforcement for the user plane,Quality-of-Service (QoS) handling, etc. When compared with 4G EPC, thefunctions of the UPF may resemble those of the SGW-U (Serving GatewayUser Plane function) and PGW-U (PDN Gateway User Plane function).

Other network elements may be present in system 100 to facilitatecommunication but are omitted for clarity, such as base stations, basestation controllers, mobile switching centers, dispatch applicationprocessors, and location registers such as a home location register orvisitor location register. Furthermore, other network elements that areomitted for clarity may be present to facilitate communication, such asadditional processing nodes, routers, gateways, and physical and/orwireless data links for carrying data among the various networkelements, e.g. between access nodes 110, 120 and communication network101.

The methods, systems, devices, networks, access nodes, and equipmentdescribed herein may be implemented with, contain, or be executed by oneor more computer systems and/or processing nodes. The methods describedabove may also be stored on a non-transitory computer readable medium.Many of the elements of communication system 100 may be, comprise, orinclude computers systems and/or processing nodes, including accessnodes, controller nodes, and gateway nodes described herein.

FIG. 2 illustrates an exemplary configuration of retransmissionmechanisms available for a wireless device in accordance with disclosedembodiments. A wireless device 210 communicates over a communicationlink 230 with an access node 240, which may, for example be gNodeB.Wireless device 210 and gNodeB 240 may implement protocol stacks 212 and242. The protocol stack is a set of protocols used in a communicationsnetwork and includes a hierarchy of software layers residing in eachclient and server. Although only four layers are illustrated, otherlayers (not shown) may be present. In the illustrated embodiments, apacket data convergence protocol (PDCP) layer 250 is on top of theprotocol stack. A radio link control (RLC) layer 252 sits below the PDCPlayer 250. A MAC layer 254 sits below the RLC layer 252 and a physical(PHY) layer 256 sits below the MAC layer 256.

The PHY layer 256 provides services to the MAC layer and supportsdownlink (gNodeB-to-UE), uplink (UE-to-gNodeB) and side link (UE-to-UE)communications. Of the other illustrated layers, each has aretransmission mechanism. A first retransmission mechanism RI resides inthe MAC layer 254. A second retransmission mechanism R2 reside at theRLC layer 252. A third retransmission mechanism R3 resides in the PDCPlayer 250.

The MAC layer 254 implements R1, or HARQ, which is the fastest of thethree illustrated retransmission systems. In 5G NR, HARQ may have adelay of less than 1 ms. NR uses an asynchronous HARQ protocol in bothdownlink and uplink, that is, the HARQ process which the downlink oruplink transmission relates to is explicitly signaled as part of thedownlink control information (DCI). The HARQ mechanism in the MAC layertargets very fast retransmissions and, consequently, feedback on successor failure of the downlink transmission is provided to the gNodeB 240after each received transport block. For uplink transmission, noexplicit feedback is required as the receiver and scheduler are in thesame node. HARQ is implemented to correct the erroneous packets comingfrom PHY layer. If the received data is erroneous, then the receiver orwireless device 210 buffers the data and requests a re-transmission fromthe sender. When the receiver receives the re-transmitted data, it thencombines it with buffered data prior to channel decoding and errordetection. The sending entity buffers the transmitted data until theacknowledgement (ACK) is received because the data needs to beretransmitted in case a negative acknowledgement (NACK) is received.Thus, HARQ is a stop and wait (SAW) protocol with multiple processes andthese can create excessive overhead.

The RLC layer 252 provides error-free delivery of data to higher layers.To accomplish this, a retransmission mechanism R2 operates between theRLC entities in the receiver and transmitter. By monitoring sequencenumbers indicated in headers of incoming protocol data units (PLUs), thereceiving RLC can identify missing PDUs (the RLC sequence number isindependent of the PDCP sequence number). Status reports are fed back tothe transmitting RLC entity, requesting retransmission of missing PDUs.Based on the received status report, the RLC entity at the transmittercan take the appropriate action and retransmit the missing PDUs ifseeded.

Although the RLC retransmission mechanism R2 is capable of handlingtransmission errors due to noise and unpredictable channel variations,error-free delivery is in most cases handled by the MAC-based HARQprotocol R1. However with HARQ, there is potential for errors in thefeedback system. RLC 252 has a slower retransmission system for dealingwith these errors but with a feedback protected by cyclic redundancychecks (CRC). Compared to the HARQ acknowledgments, the RLC statusreports are transmitted relatively infrequently. Thus, the RLCretransmission mechanism R2 is slower but more reliable than MAC HARQretransmissions.

The PDCP layer 250 supplies the retransmission mechanism R3. R3guarantees in-sequence delivery of user data and is mainly used duringhandover as RLC and MAC buffers are flushed when a handover is executed.

In embodiments described herein, R1 or HARQ, in the MAC layer, may beused as a default retransmission mechanism. However, the access node 240may selectively disable HARQ based on a comparison of a storedperformance threshold to measured performance parameters from thewireless device 210. When HARQ is disabled, the wireless device 210 mayutilize R2 or R3.

FIG. 3 depicts an access node 310 in accordance with the disclosedembodiments. In exemplary embodiments, access node 310 can include, forexample, a gNodeB or an eNodeB. Access node 310 may comprise, forexample, a macro-cell access node, such as access nodes 110 or 120described with reference to FIG. 1 . Access node 310 is illustrated ascomprising a processor 311, memory 312, transceiver 313, and antenna314. Processor 311 executes instructions stored on memory 312, whiletransceiver 313 and antenna 314 enable wireless communication with othernetwork nodes, such as wireless devices and other nodes. For example,wireless devices may initiate retransmission procedures such that thetransceivers 313 and antennas 314 receive messages from the wirelessdevices, for example, over communication links 316 and 318 and pass themessages to a mobility entity in the core network. Further, thetransceiver 313 and antenna 314 receive signals from the mobility entitysuch as an MME or AMF and pass the messages to the appropriate wirelessdevice Scheduler 315 may be provided for scheduling resources based onthe presence and performance parameters of the wireless devices. Network301 may be similar to network 101 discussed above.

In embodiments provided herein, processor 311 may operate to compare aperformance parameter of a wireless device, such as SINR to a thresholdstored in the memory 312 or in an accessible database to determine ifthe performance parameter of the wireless device meets the threshold. Inembodiments provided herein, meeting the threshold is a triggering eventfor altering a default retransmission mechanism. For example, HARQ maybe the default retransmission mechanism. However, when the performanceparameter meets the threshold, the processor 311 may determine that HARQshould be disabled and that the wireless device should rely on anotherretransmission mechanism, for example RLC or PDCP retransmissionmechanisms. The access node 310 may then utilize transceiver 313 andantenna 314 to send an instruction to the wireless device in order todisable HARQ.

FIG. 4 is a flow diagram 400 further illustrating interaction between awireless device 410 and an access node 420 in accordance withembodiments described herein. In step 1, the access node 420 sends ameasurement report including a performance parameter to the access nodeor base station 420. In step 2, the access node 420 retrieves aperformance parameter threshold, and in step 3, the access node 420compares the received measurement to the stored threshold. In step 4,the access node 420 selects a retransmission method based on thecomparison. In step 5, the access node 420 sends an instruction to thewireless devices to use the selected retransmission method.

Upon receipt of the instruction at the wireless device 410, the wirelessdevice processes the instruction in step 6. Subsequently, when aretransmission request is sent by the wireless device 410 in step 7, thewireless device sends the retransmission request using the methodselected by the access node 420 as instructed in step 5.

In the scenario described herein, the wireless device 410 may, forexample, be moving closer to the access node 420. Thus, at a locationclose to the access node 420, the wireless device 410 may send aperformance parameter that meets a predetermined threshold. Thus, inselecting the retransmission method in step 4, the access node 420 maydisable MAC HARQ retransmissions. Accordingly, the instruction mayeither inform the wireless device 410 that MAC HARQ transmissions havebeen disabled, and/or instruct the wireless device 410 to utilize aspecific retransmission method, such as an RLC retransmission method.However, when the wireless device 410 is further from the access node420 or an area with interference from a neighboring cell, theperformance parameter measured by the wireless device 410 may not meetthe predetermined threshold. In this case, the wireless device 410 maycontinue to use a default retransmission method, which may, for examplebe HARQ. Accordingly, the procedure described herein may allow thewireless device 410 to use a slower retransmission method and reduce theuplink overhead when the performance parameter of the wireless devicemeets the threshold.

The disclosed methods for uplink overhead reduction are furtherdescribed with reference to FIGS. 5 and 6 below. FIG. 5 illustrates anexemplary method 500 performed by an access node for uplink overheadreduction. Method 500 may be performed by any suitable processordiscussed herein, for example, the processor 311 included in the accessnode 310 or a processor included in a controller node. For the sake ofconvenience, the method is described as being performed by the accessnode 420

Method 500 starts in step 510 when the wireless device 410 transmits ameasured performance parameter to the access node 420. The measuredperformance parameter may, for example, be a SINR measurement. Themeasurement may be made by the wireless device 410 and may be sentperiodically by the wireless device 410 to the access node 420. Thetransmission may be part of a radio resource control (RRC) connectrequest sent by the wireless device 410 or may be simultaneous with aCSI report. Alternatively, the wireless device 410 may send theperformance parameter at a scheduled interval or based on an internallystored threshold of a distance moved, a location reached, a timeexpired, or other trigger.

In step 520, the access node 420 receives the measurement and comparesthe measurement to a stored threshold. The threshold may be stored in adatabase accessible to the access node 420 and may be stored in a memoryof the access node. The threshold may be set network wide, or for aspecific cell or sector. The threshold may be based, for example, onantenna performance parameters or other network configurationparameters.

In step 530, the access node 420 determines if the measured parameterreceived from the wireless device 410 meets the stored threshold. Forexample, if the measured parameter is SINR, when the wireless device 410is sufficiently close to the access node 420, the measured SINR may meetthe stored threshold. If the measured SINR meets the stored threshold instep 530, the access node disables the HARQ retransmission method instep 540, thereby allowing the wireless device 410 to utilize analternative retransmission mechanism, such as the RLC retransmissionmethod or the PDCP retransmission method. However, if the measuredparameter does not meet the stored threshold in step 530, the wirelessdevice 410 continues to use the HARQ retransmission mechanism andcontinues to periodically update the access node 420 with respect to themeasured performance parameter.

Accordingly, in the embodiment described with respect to FIG. 5 , uplinkoverhead is reduced by allowing wireless devices experiencing strongperformance to utilize a slower retransmission method, while otherwireless devices experiencing less optimal conditions may continue touse HARQ, which is a faster retransmission method.

FIG. 6 illustrates a method 600 for uplink overhead reduction. Method600 may be performed by an access node, for example by the processor 311of the access node 310. For the sake of illustration, the method isdescribed as being performed by the access node 420 interacting withmultiple wireless devices, such as wireless device 410. Although onlyone wireless device 410 is shown as interacting with the access node420, it should be understood that the access node 420 interacts withmultiple wireless devices, such as, for example wireless devices 131,132, and 133.

In some embodiments, the method 600 is only performed after determiningthat downlink speeds meet a network designated threshold. For example,high uplink activity is common for high downlink speeds, for example,for 50 Mbps and 100 Mbps downlink streams. The high uplink activity isdue to channel quality feedback CSI, CQI and MAC HARQ processesoverhead.

In step 610, the access node 420 compares the measured performanceparameter value to a stored threshold. In embodiments set forth herein,the access node 420 may receive the measured performance parameter fromthe wireless device 410. However, in other embodiments, the access node420 may perform its own measurements or retrieve stored measurements.

In step 620, the access node 420 determines if the measured performanceparameter meets the stored threshold. For example, the access node 420may compare a measured value of SINR or RSRP with a stored threshold. Ifthe measured value meets the threshold in step 620, the access node 420may disable the HARQ retransmission method in step 630. When HARQ isdisabled for a particular wireless device, the wireless device mayutilize another retransmission mechanism, for example, the RLCretransmission mechanism. While the RLC retransmission mechanism isslower than the HARQ retransmission mechanism, the use of the RLCretransmission mechanism reduces uplink overhead. In some embodiments,the access node 420 sends a message to the wireless device 410instructing the wireless device 410 that the HARQ retransmissionmechanism has been disabled and potentially further instructing thewireless device to utilize the RLC retransmission mechanism.

Alternatively, if the measured performance parameter does not meet thestored threshold in step 620, the access node 420 may enable the HARQretransmission mechanism in step 640 when the HARQ retransmissionmechanism was previously disabled. Thus, in some instances, the wirelessdevice 410 may be moving away from the access node 420 and theperformance parameter may no longer meet the predetermined threshold. Inthis instance, a previously disabled HARQ retransmission mechanism maybe enabled by the access node 420 in step 640. Finally, in step 650, theaccess node 420 continues to receive measured performance parametersfrom multiple wireless devices or continues to acquire or generatemeasured performance parameters for the wireless devices communicatingwith the access node 420.

In some embodiments, methods 500 and 600 may include additional steps oroperations. Furthermore, the methods may include steps shown in each ofthe other methods. As one of ordinary skill in the art would understand,the methods 700 and 800 may be integrated in any useful manner.

By the methods described herein, wireless device performance can beimproved by utilizing selective retransmission mechanism for uplinkoverhead reduction. Further, the customer service level for both 4G and5G networks will improve in various scenarios.

The exemplary systems and methods described herein may be performedunder the control of a processing system executing computer-readablecodes embodied on a computer-readable recording medium or communicationsignals transmitted through a transitory medium. The computer-readablerecording medium may be any data storage device that can store datareadable by a processing system, and may include both volatile andnonvolatile media, removable and non-removable media, and media readableby a database, a computer, and various other network devices.

Examples of the computer-readable recording medium include, but are notlimited to, read-only memory (ROM), random-access memory (RAM), erasableelectrically programmable ROM (EEPROM), flash memory or other memorytechnology, holographic media or other optical disc storage, magneticstorage including magnetic tape and magnetic disk, and solid statestorage devices. The computer-readable recording medium may also bedistributed over network-coupled computer systems so that thecomputer-readable code is stored and executed in a distributed fashion.The communication signals transmitted through a transitory medium mayinclude, for example, modulated signals transmitted through wired orwireless transmission paths.

The above description and associated figures teach the best mode of theinvention. The following claims specify the scope of the invention. Notethat some aspects of the best mode may not fall within the scope of theinvention as specified by the claims. Those skilled in the art willappreciate that the features described above can be combined in variousways to form multiple variations of the invention. As a result, theinvention is not limited to the specific embodiments described above,but only by the following claims and their equivalents.

What is claimed is:
 1. A method comprising: determining a signal to noise and interference ratio (SINR) at a wireless device; comparing the SINR to a predetermined threshold; determining the SINR at the wireless device meets the predetermined threshold; and disabling a hybrid automatic repeat request (HARQ) retransmission mechanism for the wireless device.
 2. The method of claim 1, further comprising maintaining the HARQ retransmission mechanism at a media access control (MAC) layer.
 3. The method of claim 2, further comprising utilizing a radio link control (RLC) retransmission mechanism for the wireless device.
 4. The method of claim 1, further comprising receiving a SINR measurement from the wireless device.
 5. The method of claim 1, further comprising storing the predetermined threshold at an access node.
 6. The method of claim 1, further comprising determining the SINR at an additional wireless device does not meet the predetermined threshold.
 7. The method of claim 6, further comprising utilizing the HARQ retransmission mechanism for the additional wireless device.
 8. The method of claim 7, wherein the additional wireless device utilizing the HARQ retransmission mechanism is further from a serving access node than the wireless device.
 9. The method of claim 1, further comprising determining that a downlink stream meets a predetermined speed threshold prior to disabling the HARQ retransmission mechanism.
 10. The method of claim 1, further comprising signaling the wireless device from an access node to disable the HARQ retransmission mechanism.
 11. The method of claim 10, wherein the access node is a gNodeB.
 12. An access node comprising: at least one processor performing operations including, determining a signal to noise and interference ratio (SINR) at a wireless device; comparing the SINR to a predetermined threshold; determining the SINR at the wireless device meets the predetermined threshold; and disabling a hybrid automatic repeat request (HARQ) retransmission mechanism for the wireless device.
 13. The access node of claim 12, the operations further comprising maintaining the HARQ retransmission mechanism at a media access control (MAC) layer.
 14. The access node of claim 13, the operations further comprising utilizing a radio link control (RLC) retransmission mechanism for the wireless device.
 15. The access node of claim 12, the operations further comprising receiving a SINR measurement from the wireless device.
 16. The access node of claim 12, the operations further comprising storing the predetermined threshold at the access node.
 17. A non-transitory computer readable medium storing instructions that when executed by a processor cause the processor to perform operations comprising: comparing a SINR at a wireless device to a predetermined SINR threshold; utilizing a HARQ retransmission mechanism for the wireless device when the SINR does not meet the predetermined SINR threshold; and disabling the HARQ retransmission mechanism for the wireless device when the SINR meets the predetermined SINR threshold.
 18. The non-transitory computer readable medium of claim 17, the operations further comprising signaling the wireless device from an access node to disable the HARQ retransmission mechanism.
 19. The non-transitory computer readable medium of claim 18, wherein the access node is a gNodeB.
 20. The non-transitory computer readable medium of claim 17, the operations further comprising utilizing an RLC retransmission mechanism for the wireless device upon disabling the HARQ retransmission mechanism. 